These include neuregulin 1 (Nrg1, normal development of nervous system), amyloid beta precursor protein (App, neural plasticity, and synapse formation), DnaJ Heat Shock Protein Family (Hsp40) Member A3 (Dnaja3, associated with Alzheimer disease), interleukin one receptor type 1 (Il1r1, neuron migration), and neuroligin 1 (Nlgn1, synapse function). Here, NRG1 is linked to early-onset autosomal dominant Alzheimer disease.